Electronic components such as semiconductor wafer VLSI and ULSI integrated circuit devices are provided having a robust barrier layer in the device interconnects. The robust barrier layer provides excellent step coverage, low resistance and enhanced adhesion to CVD copper and the interconnect has a double structure of a layer of a barrier material and a metal layer thereon. The metal layer is preferably tungsten and is formed by replacing silicon or other such atoms on the surface of the barrier layer with tungsten metal. A layer of silicon can be formed on the barrier layer, silicon atoms can be formed on the surface by reacting the barrier layer with a silicon containing reactant or a silicon containing barrier layer can be used.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for making multilayer electronic component integrated circuit devices wherein interconnects in the devices have excellent step coverage, uniformity, low resistance and adhesion to CVD-copper comprising the steps of: forming a multilayer electronic component layer by layer with dielectric layers having openings therein with metallization formed in the openings to provide electrical connections between the layers; forming a diffusion barrier layer in the openings in the dielectric layer which diffusion barrier layer is a refractory material containing replaceable silicon atoms; forming a metal rich surface on top of the diffusion barrier layer by reacting the barrier layer with a metal containing reactant and replacing at least part of the replaceable atoms of the diffusion barrier layer with the metal of the metal containing reactant; and filling the openings in the dielectric layer with copper to provide a conductor which contacts the metallization in the dielectric layer to metallization in another layer.
2. The method of claim 1 wherein the refractory material is selected from the group consisting of titanium silicon nitride, tantalum silicon nitride and tungsten silicon nitride.
3. The method of claim 1 wherein the metal containing reactant is WF 6 .
4. The method of claim 3 wherein the refractory material is selected from the group consisting of titanium silicon nitride, tantalum silicon nitride and tungsten silicon nitride.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
April 29, 2003
May 3, 2005
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